Aminofunctional silicones are widely used in hair care products to provide various aesthetic benefits. Formulators of hair care products are continuously seeking improvements in consumer perceivable benefits of such products. As such, there is an ongoing need to identify new aminofunctional silicones that can provide consumer perceived conditioning benefits in a variety of hair care formulations. Any improved aminofunctional silicone composition should also be easily incorporated into hair care products while not affecting the storage stability of the product. In particular, certain silicones may reduce the viscosity of hair care products upon storage. Thus, there is a further need to identify aminofunctional silicone compositions that provide consumer perceivable conditioning benefits in formulated hair care products that are storage stabile.
Reducing the presence of solvents, un-reacted siloxanes, catalyst residues, cyclic polymerization byproducts, and other impurities in aminofunctional silicones is another ongoing challenge in the art. The need to reduce such impurities may arise, among other reasons, when such impurities are incompatible with downstream applications (for example, medical, cosmetic, and personal care applications), where the presence of such impurities would reduce the stability of the product, or where regulatory requirements require removal or reduction of their presence. In particular, there is an interest to reduce the presence of cyclosiloxanes, such as octamethylcyclotetrasiloxanes (D4) and decamethylcyclopentasiloxanes (D5), in aminofunctional silicones compositions. In many instances D4 and D5 may be present in the process to prepare the aminofunctional silicones, alternatively they may be produced from side reactions upon storing the aminofunctional silicone composition.